> Thanks a lot for your answer!
>
> However, I have no idea why, but I still get:
>
> .      Preamble
> 1.   ChapterOne
> 1.1. Section

Seems ConTeXt is not testing if there is there is no number, you could

\setuplist
[chapter,section,...]
[numbercommand=\DotAfterNumber]

\def\DotAfterNumber#1{\doiftext{#1}{#1.}}

Wolfgang
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